Doctors often use misoprostol for cervical preparation prior to surgical abortion (vacuum aspiration). Until now, however, there were no studies large enough to determine whether the drug reduces the risk of serious complications, either immediate or delayed, according to background information in the study published in the March 8 online edition of The Lancet.

For the study, researchers from the World Health Organization (WHO) in Geneva compared rates of complications among nearly 5,000 women in nine countries who underwent surgical abortion before 12 weeks of gestation. Complications included cervical tear, uterine perforation, incomplete abortion and pelvic inflammatory disease.

Women were randomly assigned to receive either vaginal misoprostol or an inactive "placebo" three hours before the procedure.

The women in the misoprostol group were nearly one-third less likely to experience one or more complications compared to the women who received a placebo, and the risk of incomplete abortion was nearly three times higher among the women in the placebo group, the investigators found.

Women in the misoprostol group, however, were more likely to experience abdominal pain, vaginal bleeding and nausea in the three hours before surgery.

"Misoprostol reduced the overall incidence of complications, particularly incomplete abortions and unscheduled clinic visits and hospital admissions, after abortion," concluded study author Eduardo Bergel and colleagues, in a journal news release. "Providers should be aware of the side effects of the drug and inform women about these effects."

In an accompanying editorial, Dr. Allan Templeton, professor of obstetrics and gynecology at the University of Aberdeen in Scotland, wrote: "The important ongoing issue is . . . the balance between effectiveness of the procedure and the side effects of misoprostol, which will include abdominal cramps and vaginal bleeding in most women, although not to the extent of needing medical intervention before surgery."

The findings of this study suggest that "routine pharmaceutical dilation of the cervix should be recommended as an integral part of surgical abortion in all women," Templeton added.